Miniaturised fuel cells could replace phone batteries

Researchers at POSTECH have developed a miniaturised solid oxide fuel cell (SOFC) to replace lithium-ion batteries in drones, smartphones, laptops and other small electronic devices.

The SOFC, referred to as a third-generation fuel cell, has been intensively studied since it has a simple structure and no problems with corrosion or loss of the electrolyte. This fuel cell converts hydrogen into electricity by oxygen-ion migration to fuel electrodes through an oxide electrolyte. Typically, silicon has been used after lithography and etching as a supporting component of small oxide fuel cells. This design, however, has shown rapid degradation or poor durability due to thermal-expansion mismatch with the electrolyte, and thus, it cannot be used in actual devices that require fast on/off.

The technology, developed by Professor Gyeong Man Choi (Dept. of Materials Science and Engineering) and his research team at POSTECH, combines porous stainless steel, which is thermally and mechanically strong and highly stable to oxidation/reduction reactions, with thin-film electrolyte and electrodes of minimal heat capacity. Performance and durability were increased simultaneously. In addition, the fuel cells are made by a combination of tape casting-lamination-cofiring (TLC) techniques that are commercially viable for large-scale SOFC.

The fuel cells exhibited a high power density of ~560 mW cm^-2 at 550°C. The research team expects this fuel cell may be suitable for portable electronic devices such as smartphones, laptops and drones that require high power density and quick on/off. They also expect to develop large and inexpensive fuel cells for a power source of next-generation automotive.

With this fuel cell, drones can fly more than one hour, and the team expects to have smartphones that charge only once a week.

Source

Originally published here.